To daniel



U'ALIPERS.

Patented Apr. 1,1884.

2 Sheets-Sheet. 2.

(No Model.)

` W. A. WHTE.'

GALIPBRS. No. 296,259.4 Patented Apr. 1, 1884.

UNITED Srn'rns WILLIAM A. -WHITE, OF ATHOL, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO DANIEL APPLETON NEVVTOII, OF SAME PLAGE.

carretes.v

SPECIFICATION forming part of Letters Patent No. 296,259, dated April l, 1884. Application filed `Lllehruary 4, 17884. (No model.)

.To @ZZ whom, t may concern.

Be it known that I, WILLIAM A. WHITE, a citizen oi the United States, residing at Athol, in the county of Vorcester and State of Massachusetts, have invented new and useful Improvementsin Calipers andSirnilar Measuring- Instruments, of which the following is a speciiieation.

This invention relates to that class of calipers or other measuring-instruments having a pair of limbs in which the adjustment is effected through the medium of segmental racks and a pinion.

The object of my invention is 'to improve the construction and arrangement of parts, whereby the limbs and the Shanks beyond their pivot lie in the saine horizontal plane with their surfaces in Contact, while the axis ofthe pinion is parallel to the axis of the pivot ofthe limbs and at right angles to the limbs themselves, thus rendering the instrument neat and symmetrical in appearance and presenting the finger-piece of the pinion in such position relative to the limbs that the pinion can be rotatedand the instrument manipulated with great facility.

Another object of the invention is to provide calipers or other limbed measuring-instruments in which the shanks beyond the pivot of the limbs lie in direct contact and in the plane of the limbs themselves with a rackand-pinion Vmechanism for eilecting kthe adjustment of the limbs and a screw-nut for clamping the Shanks in contact to hold the limbs in a fixed position after adjustment, the

arrangement being such that the axes of the pinion and of the clamping screw and nut are in planes parallel. to the axis of the pivot joining the limbs and at right angles to the limbs themselves, whereby a neat and symmetrical appearance is imparted to the instrument and the adjusting and clamping devices presented in most 'convenient position relative to the limbs, thus aording convenient facilities for adjusting and holding the limbs.

.Another object of the invention is to provide a two-limbed measuring-instrument having a rack-and-pinion mechanism for adjusting the limbs with a clamping device mounted on the axis of the pinion for holding the limbs in their adjusted position.

The objects of my invention are accomplished in the manner and by the means hereinafter described and claimed, reference being had to the accompanying drawings, in which- Figure l is a perspective view of a pair of calipers embodying my invention; Fig. 2, a vertical central sectional view of the same, taken through the axis of the pivot connecting the limbs; Fig. 3, perspective views of the parts detached; Fig. 4, a perspective View, showing a modification ofthe invention; Fig. 5, a vertical central sectional view of the same, taken through the axis of the pivot connecting the limbs; and Fig. 6, perspective views of the parts detached.

Referring to the lirst three iigures of the drawings, the numbers l and 2 indicate the limbs oi' a calipers connected together by a pivot-pin, 3, each limb being extended beyond the pivot into a broad ilat shank, 4, having segmental slots 5. The inner edge of one slot and the outer edge of the, other slot are each provided with a series oi' rack-teeth, 6, the remaining edges being left smooth or plane. In the slot is arranged a pinion, 7, which is of a length exactly coinciding with the thickness of the metal at the edges ofthe slots, and of a di` ameter equaling the width of the slots, so that -one end of the pinion will engage the outer rack-teeth and the other end the inner rackteeth ofthe respective Shanks. Thepinion is rigid on a collar, 8, resting against the outer vside of the shank on'the limb 1, said collar overlapping the edges of the slot in said shank and rigid with a milled head, 9, which constitutes a finger-piece by which to roll the pinion in engagement with the rack-teeth, and thus adjust the points l0 of the two limbs toward or from each other, according to the direction in which the pinion is rolled, as will be obvious. From the end of the pinion which is opposite to collar 8 extends an attached screw-threaded pin, l1, which projects loosely through a collar, l2, resting upon the shank of the llimb 2 and overlapping the edges of the slot in said shank, and upon the threaded pin is a screw-nut, 13, having. a milled head, all in such manner thatby screwing upthej nut against the collar l2 the adjacent'surfaces of the two shanks will be clamped and presenting a large i'rictional contogether,

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tact. rIhe limbs will be thereby held or clamped in the position to which they have been adj usted by the rack-and-pinion mechanism. If the screw-nut be turned to loosen the collar 12,the lugs are then perfectly free to be adj usted by the racks and pinion. rlhis construction enables both of the points of the limbs to be uniformly moved toward or from each other,which is effected by holding the instrument either at the connecting-pivot or by the screw-nut, and rolling the pinion through the medium of its finger-piece.

In the modification shown in Figs. 4, 5, and 6 the limbsl and 2 are connected at their pivotal point by a pivot-pin, 14, extending through the limbs, and having a screw-threaded end, 15, on which the screw-nut 13 is arranged, said nut having a cavity which receives a spring coiled on the pivot-pin. The shank 4 of the limb 1 has at its upper end a housing or casing containing a pinion, 7, mounted on an axis, which extends through the outer side of the housing, and is rigid with the shank of a milled head, 9, which constitutes a finger-piece by which to rotate the pinion in its housing. 'Ihe housing projects down at the front in the form of a strap, 16, overlying the shank 4 of the limb 2, and connected with the pivot-pin 14 beneath its head, thus forming a guideway for the movements of the shank of the limb 2, the outer -edge of said shank being of segmental shape,

and constructed with rack-teeth 6. By rotating the pinion through its nger-piece the points of the limbs will be adj usted toward or from each other, according to the direction in which the pinion is rotated, and when the proper adjustment is effected the adjacent surfaces of the shanks of the limbs are clamped upon each other by the screw-nut 18, and through their frictional con'tact the limbs are held to their adjusted position.

It will be seen that the limbs and their shanks respectively lie in the same horizontal plane with the adjacent surfaces of the shanks in contact, while the axis of the operating-pinion is parallel to the axis of the pivot connecting the limbs, and at right angles to the limbs themselves, by which arrangement the instrument is rendered neat and symmetrical in appearance and the parts brought into such relative position as to afford every facility for the convenient adjustment and manipulation of the instrument.

Having thus described my invention, what I claim is 1. A measuring-instrument composed of two limbs connected by a pivot, and having shanks projecting boyond the pivot and in contact with each other, and provided with a rackand-pinion mechanism for adjusting the limbs, said pinion having its axis arranged parallel Yto the axis of the pivot connecting the limbs, and at right angles to the limbs themselves, substantially as described.

2. A measuring-instrument composed of two limbs connected by a pivot, and having shanks the pivot and in contact with each other, combined with rackandpinion mechanism on said shanks for adjusting the limbs, and means whereby the shanks may be clamped upon each other for holding the limbs in their adj usted position, substantially as described. V

3. Ameasuring-inst-rument consisting'of two limbs connected by a pivot, and having shanks projecting beyond the pivot and in contact with each other, a rack-and-pinion mechanism on the shanks for adjusting the limbs, said projecting beyond pinion having its axis parallel to the axis of 8o the pivot connecting the limbs, and at right angles to the limbs themselves, and means for clamping the said shanks into frictional contact for holding the limbs in their adjusted position, substantially as described.

4. A measuring-instrument consisting of two limbs connected by a pivot, and having shanks projecting beyond the pivot and in direct contact with each other, a rack-and-pinion mechanism on the shanks for adjusting the limbs, and pinion having its axis parallel to the axis of the pivot connecting the limbs, and va screw nut and pin for clamping the shanks together to hold the limbs in their adjusted position, substantially as described. v

5. A measuring-instrument consisting of two limbs connected by a pivot, and having shanks projecting beyond the pivot and in direct contact, a rack-and-pinion mechanism for adjusting the limbs, and a screw nut and pin for clamping the shanks together to hold the limbs in their adjusted position, and screw nut and pin having their axes arranged parallel to the axis of the pivot connecting the limbs, substantially as described.

, 6. Ameasuring-instrument consisting of two limbs connected by a pivot, with shanks beyond the pivots provided with slots having teeth at their edges, a pinion arranged in said slots and engaging the teeth, and a nger-piece for rolling the pinion to adjust the limbs, substantially as described.

7. Ameasuring-instrument consisting of two pivoted limbs, with shanks beyond the limbs provided with slots having teeth at their edges, a pinion in said slots and engaging the teeth, a finger-piece for rolling the pinion to adjust the limbs, and means for holding the limbs in position after their adjustment, substantially as described.

In testimony whereof I have hereunto set my hand and seal in the presence of two subscribing witnesses.

WILLIAM A. WHITE. [1.. s]

said pinion IOO IXO 

